The exhaust isnt smoking on cold startup
This, makes me think this......
Yeah black is running rich.
Turbo isn't doing its job for some reason, ECU thinks it is, dumps in more fuel than can be burnt.
Either:
- blockage (intercooler)
- some sensor not plugged in
- some pipe not connected/split
Or:
Knackered injector and it's been smoking for ages, the resulting coke killed the turbo.
I refilled just a few miles back as i was on reserve.
It runs very well, with new turbo and stage 1 etc, but i'll get vcds on it this week too, see if i can figure out how to get a graph of expected vs actual boost. And egr figures too
VCDS tells you expected vs actual boost and the same for most readings. Of course the 'actual' is only what its sensors are telling it, so a bad sensor would not show up here necessarily (depending on what it is).
It runs very well, with new turbo and stage 1 etc
Wait.
You had a knackered turbo.
The garage exchanged the CHRA, didn't clean out the intercooler, dumped a load of snake oil into the fuel and performed a "stage 1" remap?
This just gets better and better *facepalm*
who said anything about a garage?
sometimes you gotta do things yourself.
Like fix a puncture. Or learn how to ride around a corner, one has to think for oneself
I dont want a garage in charge of my financial situation if i can help it
My apologies, I wrongly assumed the "people you talked to" were mechanics and had some hand in the job.
So to revise:
You had a knackered turbo after some unknown foreign material got in and caused enough damage to bend the fins.
You exchanged the CHRA, didn’t clean out the intercooler, didn't investigate what got into the turbo, how it got in there or where it subsequently ended up, dumped a load of snake oil into the fuel and performed a “stage 1” whatever that is?
Now it's running like shit because presumably whatever caused the initial damage is still in there and has either been ingested by the engine (or still is) or is trapped in your intercooler, possibly in bits.
I dont want a garage in charge of my financial situation if i can help it
In this instance I'd say you're costing yourself more in the long run. If there is loose foreign material in there then where do you think it's going to end up? Your valve seats and the hot side of the turbo before the cat and DPF (if applicable). If it's oil then you could be clogging your DPF and poisoning your CAT. This is why you are supposed to check everything downstream before restarting and you especially DO NOT restart until you know exactly what caused the turbo to fail.
It's not a difficult job after pulling a turbo. It's two pipes and some brackets, worst case it's water cooled and you need to change the coolant. Big deal.
I used to clean out my RD350 'spannies with a caustic soda solution, tie wrap some plastic over the header ends and fill them up. Please do check what your exhaust is made of before doing the same, mine were all steel so no destructive chemical reactions.
The best way I have found to work out when your car smokes is to drive at night on an unlit road in front of a willing friend, their headlights pick it out much better than you ever can in daylight. Quite a short run can cover cold to warm, under load and over-run, which has helped me diagnose problems in the past.
Possibly dumb question, but if a turbo lets go is it inevitable that it dumps oil into both hot and cold sides?
no, its now running better than ever, seems to have some residual oil in the silencer to clean out.
I dont recall exactly what the guy in the turbo shop said, but definitely got the impression that all was good to go, him having seen the new turbo and old chra
it is a major job to remove the intercooler, and the garage would want more than the car is worth
it is obvious that the damage was done to the exhaust side of the turbo, so the intercooler should not be affected, no?
Its done 300miles now
But thanks for your insight
it is obvious that the damage was done to the exhaust side of the turbo
You haven't told us that up until this point, you could have saved a lot of pointless conjecture if you had.
I'm still really not sure how an intercooler is a major job after removing and stripping a turbo, it's not even French!
I got no further with this, but have a couple more questions
The smoke from exhaust is mostly when its idling, so;
Could the oil feed to the turbo,create this smoke at idle?
If the PCV/CCV valve is blocked/dirty, would this create a smoky exhaust at idle??
Im now thinking that the turbo is not a problem, possibly too much pressure/blowby from a worn engine is creating the smoke.
Does this sound feasible?
I really need to get the emissions down for an MOT test soon
What does your oil look like - any fuel in the oil when left to settle ? <span style="text-align: center;">I</span>
<span style="text-align: center;"> know of a couple of engines I know well (not Audis) that over fuel smoke at idle would have me looking at injector leak off tests - cheap test. Will probably give an expensive diagnosis that no one wants to receive on an old car. </span>
But then it's only cheap if your engine is of the type you can do a leak off test on without upsetting the fuel rail pressures.
oil looks good- just changed it.
smoke is more greyish -at idle, or under slight load at 1500rpm
Id like to check the injectors and/or compression. Even if its too much to fix it, I want to know where the probleem is.
Dont know exactly what happened with the turbo.
Prior to that i tried mr muscle to clean some carbon out of it
I mean, I'm not an expert but...
Oven cleaner is an old fix for clagged up vanes, that was in the pre-DPF days though.
Grey smoke at idle sounds like oil leak. It's a sort of fixed quantity so when you rev up it gets blown away in the exhaust. Could be something like valve stems leaking. Burning oil has a nasty acrid smell to it, a bit like burning rubber or chemicals or something. Unburned diesel smoke is sooty and sort of... Feels different in your nose.
if it was valve stem oil seals leaking, how would i diagnose and is it a simple fix?
Or is there an additive to fix it for a while?
I don't know, you'd probably have to rebuild the head to fix them. I think there are additives that claim to be able to fix things like that but who knows if they work.
That's just one of the things that can cause oil to get into the combustion chamber. Another is worn piston rings.
Some pictures in this video. Ignore the stuff about vacuum sucking oil in, probably doesn't apply to you. Plus those examples are horrendous.
thats a good informative video. if all videos were like that...
im not burning any oil.
Stem seals will clear after a few minutes, my C8 smoked like a chimney. Start it up again and it should stay clear but will build up again after an hour or so of sitting.
Grey smoke could be oil or fuel.
On something without a DPF, an experienced nose can easily tell the difference, with a DPF, not so much.
It sounds more like a fuelling issue, but without seeing the vehicle in person, it's pure guesswork.
First rule of remapping is to have your engine running fault free first. Will the company that supplied the map temporarily put the car back to stock whilst you diagnose the smoking problem?
Remapping just strips out the carefully balanced mapping that keeps your emissions down, we've all notice those modified cars that have clearly been badly mapped with a stinky exhaust and a black sooty arse. Our fleet at work was all given an 'eco' tune and the Vauxhall's in particular had an acrid smelling exhaust that you'd always notice in the yard.
I had my first van mapped and yes, it made it much quicker, but I'm not doing my current van for the above reasons.
It will smoke at idle when warm,but I drove for an hour,and it was still smoking at idle, so maybe not stem seals.
I could restore the original map.
And it doesnt have a dpf
Diesel smoke smells a bit like candle smoke. Oil smoke is acrid and absolutely horrible.
This stage 1 mod. Is it a box that ypu wire in? Or an actual remap? Those boxes just mess with the rail pressure, potentially causing smog at idle
this is an actual remap, which was done before the turbo blew.
Generic map or Dyno derived map specific to the outputs of the car ?
Generic maps downloaded off the interwebs can have similar effects to plug in boxes especially on an older car with wear and sensors not reporting accurately./the same as the car the tune was derived on.
How long before turbo blew ? Was it running smoke free prior to turbo blowing ? If so likely a white elephant
I was going to say that smoke can be cause by not enough air/too much fuel, which would be the case under high load but at idle there is likely to always be enough air to burn what little fuel is injected. If it over fuelled, that fuel would still be burned leading to higher revs and then the car would simply reduce injection further to achieve the specified revs.
TBH, even quite "well respected" remaps just switch off a few safeties and over fuel like a MF.
Especially on diesels.
If it over fuelled, that fuel would still be burned leading to higher revs and then the car would simply reduce injection further to achieve the specified revs.
Hence a leak off test. Injectors have a service life. Generally they fail to atomise sufficiently but people dont notice the decline and just live with it. Often though they fail to close and just let fuel through the system which is ejected as smoke - the car doesn't see that fuel being input as it's told the injector to restrict flow but can't get it low enough
Yeah if it's leaking at the wrong point in the cycle that makes sense.
Diesel smoke smells a bit like candle smoke. Oil smoke is acrid and absolutely horrible
Both diesel and engine oil can both cause those types of smoke, as the smoke depends on what's causing it.
Diesel or oil that go through the combustion chamber without being burnt correctly are likely to lead to white/grey smoke, that typically has a quite eye stinging effect. Excess oil will typically cause blue smoke. Excess fuel, or more precisely lack of oxygen, will typically cause excess soot and black smoke.
A competent diesel tech should be able to quite quickly establish which type of smoke it is, but finding the root cause isn't always easy.
Did the fault exist before the turbo failed?
It could be the turbo failing has drawn attention to the smoke, and the smoke was there before the turbo failed, or it could be the turbo failing has damaged something else, or the turbo failing is the symptom of something else.
The fact the car has been remapped, means very few garages will be willing to get involved in diagnostics, as it's just too risky.
checking the injectors with VCDS I found;
Group 013: Idle Stabilization (Injection Quantity Deviation)
0.00 mg/str Injection Quantity Deviation Cyl. 1
-1.88 mg/str Injection Quantity Deviation Cyl. 2
0.80 mg/str Injection Quantity Deviation Cyl. 3
1.06 mg/str Injection Quantity Deviation Cyl. 4
From what I can gather, a deviation of 1mg/str is not good enough, something needs to be done with the injectors.
I did not find a way to do a compression test with vcds
As regards the leakoff tests the cheap adaptors on ebay seem to be for common rail diesels, which mine is not
Its a bit too windy for me to judge the smoke colour and smell
If it's not common rail what is it, 20odd year old PDF?
Don't take this the wrong way but you're a really poor communicator, you've given next to no info, people have speculated, you drop a breadcrumb and repeat.
What car is it?
What year is it?
What engine is it?
What was the history before remap?
What exactly happened after remap?
Without useful info people can't give useful advice.
ok, yes i dont want to give too much info to generalise the problem, was trying to keep things specific to my outlook, i cant deal with evry possibility.i come to a conclusion, then i need to expand on/solve that before i move on
Its a 15yr old a4 2.0tdi 16v pd140, history unknown, 170k miles
Probably should have checked evryting before remap, did mr muscle thing, but something,probably loose bits of carbon went into and wrecked the turbo, so got a new chra and cleaned as best ass i can.the vnt vanes were carbon heavy
Okay, doubt loose carbon lunched the turbo, my old Civic was terrible for the same thing and they would generally seize up leading to over/under boosting. You would need to feed it harder stuff than the crap off the vanes to worry it in a one off situation.
First things first are the vanes moving freely? That would be my first check, if it's mechanical activation it's a simple check, if it's vac then you may need to mess about. In fact if it's vac then check you don't have a leak, if it's not opening up then you could be under fuelling (though I'd expect it to realise thats the case but PDs were easy to "tune" because they weren't particularly fussy).
the vanes etc are clean and moving fine now, vac is good and n o under/overboost codes, as I said i didn want to complicate the discussion with things that werent relevant, so trying to keep it to the point
google is a minefield
Nothing to do with turbo operation as it's happening at idle. Possibly a turbo oil seal leak, but it's now looking like injectors I reckon.
True, got a bit excited there. Been a long day.
Liqui Moly Diesel Purge looks like my next logical step, to try to clean the injectors.
And a compression test if i can find a way to do that
Compression test needs specialist gear AFAIK, you need to remove an injector (or perhaps glow plug) and fit a pressure gauge in place then turn the engine over manually to check the pressure it can create in the cylinder. Someone correct me if I'm wrong.
I had a Berlingo that eventually started to smoke white smoke really badly after it had idled for a while. We are talking world war 1 tank levels of smoke. Embarrassing and dangerous.
The garage thought that it was the turbo that was faulty so replaced that. It was not a pleasant feeling to find it was exactly the same after the new turbo.
Further investigations via a compression test found that one of the injectors was leaking fuel into the cylinder. The constant flushing of diesel in the cylinder had caused the cylinder wall to become scored.
I traded it in for 300 quid.
Update
There was not enough room to use the compression tester I got.
Anyway i tried the diesel purge, the youtube method.2nd time it worked,1st time I was not as prepared as i thought. (TIP- watch all the youtube videos on it you can, if it can go wrong, it will go wrong)
Fortunately, an old diesel mechanic just happened to be around, miles from anywhere,and he gave me a lift home and told me how to start the car again.
With VCDS the timing was altered slightly,to improve things
The emissions were still too high,so I got a couple more liqui moly products,and thats lowered the emissions a lot, so now its all good, and I can sell the other car, go on holiday, etc.
Thanks so much for all your help.
Which products?
diesel purge, motor oil saver, and oil smoke stop
oil saver "takes 300-500 miles to work"
Liqui Moly suggested to use Motor Clean also,but you need to change oil when you do that,and id only just put the oil saver in.So thats waiting for next oil change